What happens when tens of thousands of people buy tickets to an event that many have no interest in attending?

The answer lies in tickets for sale on sites like StubHub for as low as $6.55 to next week’s Chargers vs. Cardinals exhibition game, in which the starting players are expected to sit out most, if not all of the game. Many seats are going for 85 percent off the face value on the secondary market.

“It really does create a question about the value of preseason for fans,” said Miro Copic, a marketing lecturer at the San Diego State University College of Business Administration. “It’s almost like the NFL could offer them for free as a PR activity. One of the things that should be considered is how do you make preseason a way to engage fans who otherwise may not afford a Charger game, or are now willing to get apparel?”

The reason there are so many tickets available for such a low price is because of what economists call bundling. A fan who buys season tickets to the Chargers is required to also buy tickets to the exhibition games at prices near face value, even if they don’t want them.

Bundling is a somewhat common practice in the business world. Think cable television, in which you pay for 300 channels to be able to watch the 15 you want. Or the Microsoft Office Suite — in order to buy Word, you need to pay for Excel and PowerPoint, even if you never plan to make a spreadsheet or a slide show.

“You have two different products basically that you sell as a package,” said Alan Gin, economist at the University of San Diego. “Most of the time you can’t necessarily detach these things and sell the part that you don’t want.”

Unlike cable television or computer programs, tickets can be separated and sold on the secondary market. The problem for the preseason is there’s not much demand to meet the supply.

Next week’s Chargers vs. Cardinals game is the fourth and final exhibition game, which is notorious for a lack of starters as teams choose their final roster spots and don’t want to risk injury. Add to that, the game’s on a Thursday, a work night, and the Chargers and Cardinals meet 11 days later for the regular season opener on Monday Night Football. They undoubtedly won’t show each other much.

“It’s got all the factors of being a dud,” said John Nelson, owner of Premier Tickets in Mission Valley. “I’m prepared to take $10 a ticket just to get something.”

Nelson’s price is still well below face value for general tickets to the game. Seats range from $47 to $117 before fees, and are available on every level of Qualcomm Stadium, according to the Chargers Ticketmaster site.

On StubHub, where fans list their tickets for sale, a prime seat on the 50-yard line main level for next Thursday’s exhibition is available for $18.89, with no fees. That’s a stark contrast to the Sept. 14 regular season home opener versus the defending Super Bowl champion Seattle Seahawks, in which 50-yard line main level seats on StubHub start at $277.